A method for extracting a direct current carrier communication signal
By employing a signal extraction method consisting of a rectifier bridge, DC blocking capacitors, and differential amplifier circuits, effective isolation and amplification of DC carrier signals were achieved, solving the problem of signal susceptibility to interference and improving communication stability.
Patent Information
- Application Number
- CN202210643895.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-06-09
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2042-06-09
AI Technical Summary
In DC power supply systems, DC carrier signals are susceptible to interference from power signals and cannot be effectively isolated, leading to communication abnormalities. Traditional A/D sampling circuits have small signal amplitudes that are easily interfered with and cannot achieve effective isolation between power signals and control signals.
The DC carrier signal is sampled and amplified using a rectifier bridge, DC blocking capacitor, signal extraction capacitor, differential amplifier circuit, and RC filter circuit. The signal is then analyzed by the MCU controller to control the switching and brightness of the LED lights. Signal isolation is achieved by utilizing the DC blocking and AC passing characteristics of the capacitor.
It effectively isolates control signals from power signals, avoids lightning surge impacts, improves the extraction capability of DC carrier communication signals, and solves the signal interference problem.
Smart Images
Figure CN115276714B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the direct current power supply related technical field, especially to a direct current carrier communication signal extraction method. BACKGROUND
[0002] The direct current power supply system is a power supply system that obtains adjustable direct current by rectifying three-phase alternating current through internal power supply rectifier modules, and supplies power to lamps and lanterns through power cables.
[0003] The communication between the direct current power supply system and the LED lamp equipment is usually achieved by using wireless communication such as ZigBee, NB-IoT, LoRa or wired communication such as PLC (power line carrier), RS485 and DALI to realize the control of the LED lamp equipment. The above communication methods need to increase a separate communication module in the LED lamp equipment to realize light control. Although the above communication methods are simple to implement, the implementation cost is high, and some communication methods are easily disturbed, resulting in communication abnormalities.
[0004] On the output direct current power supply line of the direct current power supply system, a special communication method using power lines as information transmission media for voice or data transmission is called direct current carrier communication. The method of using the rectifier unit in the direct current power supply system to realize the issuance of control instructions by adjusting the output voltage (voltage jumps at rated amplitude and frequency) is called low-frequency direct current power carrier.
[0005] In the low-frequency direct current power carrier system, the output voltage of the rectifier unit in the direct current power supply system is relatively high, the carrier signal amplitude during communication is relatively small (the carrier signal voltage amplitude should not be too large, otherwise the requirement for the rectifier module is relatively high, and the signal transmission rate will also be reduced), and the traditional A / D sampling circuit samples the communication signal after resistance division. Since the proportion of the communication carrier signal to the power supply voltage is very small, about 5%, the carrier signal amplitude that can be sampled after resistance division will be greatly reduced, so that the A / D sampled signal is easily disturbed by the power signal, resulting in data transmission failure. At the same time, the direct current carrier communication signal extraction circuit using resistance division cannot realize effective isolation of power conversion and control signal. SUMMARY
[0006] The present application is to overcome the above-mentioned deficiencies in the prior art, and provides a direct current carrier communication signal extraction method capable of effective signal isolation.
[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:
[0008] A direct current carrier communication signal extraction method, specifically comprising the following steps:
[0009] (1) DC carrier signal extraction: the positive and negative poles of the DC bus are connected with the input end of the rectifier bridge stack for rectification, and the output end of the rectifier bridge stack is connected with the signal extraction capacitor through the DC isolation capacitor, and the carrier signal is sampled;
[0010] (2) DC carrier signal amplification: the signal extraction capacitor is respectively connected with the differential amplification circuit and the RC filter circuit, the sampled carrier signal is differentially amplified with the average value after RC filtering, and a square wave signal is obtained;
[0011] (3) MCU control circuit control: the square wave signal is transmitted to the MCU control circuit for analysis through the voltage follower, the MCU control circuit analyzes the DC carrier signal, and controls the switching and dimming of the LED lamp.
[0012] The method uses the DC isolation and AC transmission characteristics of the capacitor itself to extract the DC carrier signal, and gives the signal to the MCU controller after differential amplification. The MCU controller analyzes the DC carrier signal to control the switching and brightness of the LED lamp. This method not only solves the problem that the DC carrier signal sampling is easily disturbed by the power signal, but also ensures that the control signal and the power signal are effectively isolated, avoiding the impact of power circuit lightning surge on the control circuit.
[0013] As preferred, in step (1), the circuit for DC carrier signal extraction is as follows: it comprises a DC bus, a rectifier bridge stack BD1, a DC isolation capacitor C1, a DC isolation capacitor C3 and a signal extraction capacitor C2, the positive and negative poles of the DC bus are connected with the input end of the rectifier bridge stack BD1, the output end positive pole of the rectifier bridge stack BD1 is connected with one end of the DC isolation capacitor C1, the output end negative pole of the rectifier bridge stack BD1 is connected with one end of the DC isolation capacitor C3, the other end of the DC isolation capacitor C1 is connected with one end of the signal extraction capacitor C2, the other end of the DC isolation capacitor C3 is connected with the other end of the signal extraction capacitor C2, the connection between the DC isolation capacitor C3 and the signal extraction capacitor C2 is grounded, and one end of the signal extraction capacitor C2 is respectively connected with the differential amplification circuit and the RC filter circuit.
[0014] As preferred, in step (2), the differential amplification circuit comprises: an operational amplifier OP1A, an operational amplifier OP1B and an operational amplifier OP2A, wherein one end of the signal extraction capacitor C2 is respectively connected with the non-inverting input end of the operational amplifier OP1A and the input end of the RC filter circuit, the output end of the RC filter circuit is connected with the non-inverting input end of the operational amplifier OP1B, the inverting input end of the operational amplifier OP1A and the inverting input end of the operational amplifier OP1B are connected, the output end of the operational amplifier OP1A is connected with the non-inverting input end of the operational amplifier OP2A, the output end of the operational amplifier OP1B is connected with the inverting input end of the operational amplifier OP2A, and the output end of the operational amplifier OP2A is connected with the voltage follower.
[0015] As preferred, in step (2), the circuit of the differential amplification circuit is as follows: one end of the signal extraction capacitor C2 is connected to the positive input end of the operational amplifier OP1A through the resistor R1, the output end of the RC filter circuit is connected to the positive input end of the operational amplifier OP1B through the resistor R4, the inverting input end of the operational amplifier OP1A is connected to the inverting input end of the operational amplifier OP1B through the resistor R6, the inverting input end of the operational amplifier OP1A is connected to the output end of the operational amplifier OP1A through the resistor R5, the inverting input end of the operational amplifier OP1B is connected to the output end of the operational amplifier OP1B through the resistor R7, the output end of the operational amplifier OP1A is connected to the positive input end of the operational amplifier OP2A through the resistor R8, the positive input end of the operational amplifier OP2A is connected to the ground through the resistor R9, the output end of the operational amplifier OP1B is connected to the inverting input end of the operational amplifier OP2A through the resistor R10, the inverting input end of the operational amplifier OP2A is connected to the output end of the operational amplifier OP2A through the resistor R11, and the output end of the operational amplifier OP2A is connected to the voltage follower.
[0016] As preferred, in step (2), the RC filter circuit comprises the resistor R2, the resistor R3 and the capacitor C4, wherein one end of the signal extraction capacitor C2 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to one end of the resistor R3, one end of the capacitor C4 and the positive input end of the operational amplifier OP1B respectively, and the other end of the resistor R3 and the other end of the capacitor C4 are both connected to the ground.
[0017] As preferred, in step (3), the circuit follower is the operational amplifier OP2B, wherein the output end of the operational amplifier OP2A is connected to the positive input end of the operational amplifier OP2B, the inverting input end of the operational amplifier OP2B is connected to the output end of the operational amplifier OP2B, and the output end of the operational amplifier OP2B is connected to the MCU control circuit.
[0018] The present application has the advantages that not only the problem of the direct current carrier signal sampling being easily interfered by the power signal is solved, but also the control signal and the power signal are effectively isolated, and the control circuit is prevented from being impacted by the lightning surge of the power circuit. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 is the circuit principle diagram of the present application;
[0020] Figure 2 is the circuit principle diagram of the present application. DETAILED DESCRIPTION
[0021] The present application will be further described below in combination with the drawings and specific embodiments.
[0022] AsFigure 1 、 Figure 2 In an embodiment, a direct current carrier communication signal extraction method specifically comprises the following steps:
[0023] (1) Direct current carrier signal extraction: the positive and negative poles of the direct current bus are connected to the input end of the rectifier bridge stack for rectification, and the output end of the rectifier bridge stack is connected to the direct current isolation capacitor and then connected to the signal extraction capacitor for sampling of the carrier signal;
[0024] The circuit for direct current carrier signal extraction is specifically as follows: comprising a direct current bus, a rectifier bridge stack BD1, a direct current isolation capacitor C1, a direct current isolation capacitor C3 and a signal extraction capacitor C2, the positive and negative poles of the direct current bus are connected to the input end of the rectifier bridge stack BD1, the positive output end of the rectifier bridge stack BD1 is connected to one end of the direct current isolation capacitor C1, the negative output end of the rectifier bridge stack BD1 is connected to one end of the direct current isolation capacitor C3, the other end of the direct current isolation capacitor C1 is connected to one end of the signal extraction capacitor C2, the other end of the direct current isolation capacitor C3 is connected to the other end of the signal extraction capacitor C2, the connection between the direct current isolation capacitor C3 and the signal extraction capacitor C2 is grounded, and one end of the signal extraction capacitor C2 is connected to a differential amplification circuit and an RC filter circuit respectively;
[0025] (2) Direct current carrier signal amplification: the signal extraction capacitor is connected to the differential amplification circuit and the RC filter circuit respectively, the sampled carrier signal is differentially amplified with the average value after RC filtering to obtain a square wave signal;
[0026] The differential amplification circuit comprises an operational amplifier OP1A, an operational amplifier OP1B and an operational amplifier OP2A, one end of the signal extraction capacitor C2 is connected to the non-inverting input end of the operational amplifier OP1A and the input end of the RC filter circuit respectively, the output end of the RC filter circuit is connected to the non-inverting input end of the operational amplifier OP1B, the inverting input end of the operational amplifier OP1A and the inverting input end of the operational amplifier OP1B are connected, the output end of the operational amplifier OP1A is connected to the non-inverting input end of the operational amplifier OP2A, the output end of the operational amplifier OP1B is connected to the inverting input end of the operational amplifier OP2A, and the output end of the operational amplifier OP2A is connected to a voltage follower.
[0027] The RC filter circuit comprises a resistor R2, a resistor R3 and a capacitor C4, one end of the signal extraction capacitor C2 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to one end of the resistor R3, one end of the capacitor C4 and the non-inverting input end of the operational amplifier OP1B respectively, and the other end of the resistor R3 and the other end of the capacitor C4 are both grounded.
[0028] The circuit of the differential amplification circuit is as follows: one end of a signal extraction capacitor C2 is connected to the positive input terminal of an operational amplifier OP1A through a resistor R1, the output terminal of an RC filter circuit is connected to the positive input terminal of an operational amplifier OP1B through a resistor R4, the inverting input terminal of the operational amplifier OP1A is connected to the inverting input terminal of the operational amplifier OP1B through a resistor R6, the inverting input terminal of the operational amplifier OP1A is connected to the output terminal of the operational amplifier OP1A through a resistor R5, the inverting input terminal of the operational amplifier OP1B is connected to the output terminal of the operational amplifier OP1B through a resistor R7, the output terminal of the operational amplifier OP1A is connected to the positive input terminal of an operational amplifier OP2A through a resistor R8, the positive input terminal of the operational amplifier OP2A is connected to a resistor R9 and then grounded, the output terminal of the operational amplifier OP1B is connected to the inverting input terminal of the operational amplifier OP2A through a resistor R10, the inverting input terminal of the operational amplifier OP2A is connected to the output terminal of the operational amplifier OP2A through a resistor R11, and the output terminal of the operational amplifier OP2A is connected to a voltage follower.
[0029] (3) MCU control circuit control: the square wave signal is transmitted to the MCU control circuit through the voltage follower for analysis, and the MCU control circuit controls the switching and dimming of the LED lamp after analyzing the direct current carrier signal;
[0030] The circuit follower is an operational amplifier OP2B, wherein the output terminal of the operational amplifier OP2A is connected to the positive input terminal of the operational amplifier OP2B, the inverting input terminal of the operational amplifier OP2B is connected to the output terminal of the operational amplifier OP2B, and the output terminal of the operational amplifier OP2B is connected to the MCU control circuit.
[0031] The method realizes extraction of a carrier signal on a direct current bus, and comprises a rectifier bridge stack BD1 including positive and negative conversion, a direct-current isolation capacitor C1 / C3, a signal extraction capacitor C2, an RC filter circuit (R2 / R3 / C4), a differential amplification circuit (OP1A / OP1B / OP2A) and an MCU control circuit. Two-thirds of the rectifier bridge stack BD1 are respectively connected to the positive and negative poles of the direct current bus, and one-fourth of the rectifier bridge stack BD1 is connected to the direct-current isolation capacitor C1 / C3 and the signal extraction capacitor C2. One end of the signal extraction capacitor C2 is grounded, and the other end is connected to the differential amplification circuit and the RC filter circuit. The carrier signal sampled through the signal extraction capacitor C2 is differentially amplified with the average value after RC filtering to obtain a square wave signal. The square wave signal is transmitted to the MCU control circuit for analysis through the voltage follower of OP2B. The MCU control circuit controls the switching and dimming of the LED lamp after analysis. In summary, the method uses the direct-current isolation and alternating-current transmission characteristics of the capacitor itself to extract the direct current carrier signal. The signal is differentially amplified and then given to the MCU controller. The MCU controller controls the switching and brightness of the LED lamp after analyzing the direct current carrier signal. The method not only solves the problem that the sampling of the direct current carrier signal is easily disturbed by the power signal, but also ensures effective isolation of the control signal and the power signal, avoids the control circuit from being impacted by the lightning surge of the power circuit, and improves the extraction capability of the direct current carrier communication signal.
Claims
1. A method of extracting a direct current carrier communication signal, characterized by, Specifically comprising the following steps: (1) DC carrier signal extraction: the positive and negative poles of the DC bus are connected with the input end of the rectifier bridge stack for rectification, and the output end of the rectifier bridge stack is connected with the signal extraction capacitor through the DC isolation capacitor, and then the carrier signal is sampled; the circuit for extracting the DC carrier signal is specifically as follows: comprising a DC bus, a rectifier bridge stack BD1, a DC isolation capacitor C1, a DC isolation capacitor C3 and a signal extraction capacitor C2, the positive and negative poles of the DC bus are connected with the input end of the rectifier bridge stack BD1, the positive output end of the rectifier bridge stack BD1 is connected with one end of the DC isolation capacitor C1, the negative output end of the rectifier bridge stack BD1 is connected with one end of the DC isolation capacitor C3, the other end of the DC isolation capacitor C1 is connected with one end of the signal extraction capacitor C2, the other end of the DC isolation capacitor C3 is connected with the other end of the signal extraction capacitor C2, the connection point of the DC isolation capacitor C3 and the signal extraction capacitor C2 is grounded, and one end of the signal extraction capacitor C2 is connected with a differential amplification circuit and an RC filter circuit respectively; (2) DC carrier signal amplification: the signal extraction capacitor is connected with the differential amplification circuit and the RC filter circuit respectively, the sampled carrier signal is differentially amplified with the average value after RC filtering to obtain a square wave signal; the differential amplification circuit comprises: an operational amplifier OP1A, an operational amplifier OP1B and an operational amplifier OP2A, one end of the signal extraction capacitor C2 is connected with the non-inverting input end of the operational amplifier OP1A and the input end of the RC filter circuit respectively, the output end of the RC filter circuit is connected with the non-inverting input end of the operational amplifier OP1B, the inverting input end of the operational amplifier OP1A and the inverting input end of the operational amplifier OP1B are connected, the output end of the operational amplifier OP1A is connected with the non-inverting input end of the operational amplifier OP2A, the output end of the operational amplifier OP1B is connected with the inverting input end of the operational amplifier OP2A, and the output end of the operational amplifier OP2A is connected with a voltage follower; the RC filter circuit comprises: a resistor R2, a resistor R3 and a capacitor C4, one end of the signal extraction capacitor C2 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with one end of the resistor R3, one end of the capacitor C4 and the non-inverting input end of the operational amplifier OP1B respectively, and the other end of the resistor R3 and the other end of the capacitor C4 are both grounded; (3) MCU control circuit control: the square wave signal is transmitted to the MCU control circuit for analysis through the voltage follower, the MCU control circuit controls the switching and dimming of the LED lamp after analyzing the DC carrier signal; the circuit follower is an operational amplifier OP2B, the output end of the operational amplifier OP2A is connected with the non-inverting input end of the operational amplifier OP2B, the inverting input end of the operational amplifier OP2B is connected with the output end of the operational amplifier OP2B, and the output end of the operational amplifier OP2B is connected with the MCU control circuit.
2. The method of claim 1, wherein the step of extracting the DCC signal comprises the steps of: In step (2), the circuit of the differential amplification circuit is as follows: one end of the signal extraction capacitor C2 is connected to the non-inverting input terminal of the operational amplifier OP1A through the resistor R1, the output terminal of the RC filter circuit is connected to the non-inverting input terminal of the operational amplifier OP1B through the resistor R4, the inverting input terminal of the operational amplifier OP1A is connected to the inverting input terminal of the operational amplifier OP1B through the resistor R6, the inverting input terminal of the operational amplifier OP1A is connected to the output terminal of the operational amplifier OP1A through the resistor R5, the inverting input terminal of the operational amplifier OP1B is connected to the output terminal of the operational amplifier OP1B through the resistor R7, the output terminal of the operational amplifier OP1A is connected to the non-inverting input terminal of the operational amplifier OP2A through the resistor R8, the non-inverting input terminal of the operational amplifier OP2A is connected to the ground through the resistor R9, the output terminal of the operational amplifier OP1B is connected to the inverting input terminal of the operational amplifier OP2A through the resistor R10, the inverting input terminal of the operational amplifier OP2A is connected to the output terminal of the operational amplifier OP2A through the resistor R11, and the output terminal of the operational amplifier OP2A is connected to the voltage follower.
Citation Information
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